John Calcraft (1726-72) was the son of a solicitor also John Calcraft of Grantham, and the cousin of Henry Fox (later Lord Holland), who helped him to various lucrative public offices. Calcraft worked as a clerk in the Pay Office in 1745-57, a clerk in the War Office in 1747-56, as Paymaster of widow’s pensions in 1757-62, and Commissary of Musters in 1756-63. However, despite his filial connection to Fox, and the support Fox had given his career, in the 1760s and '70s Calcraft became a supporter of the Marquis of Shelburne. There is considerable extant correspondence between Calcraft and Shelburne, and it was through this connection that Calcraft was able to forge a political career. He served as MP for Calne in 1766-68, and Rochester in 1768-72. Towards the end of his life Calcraft unsuccessfully pursued the Irish Earldom of Ormond.

In 1760 Calcraft purchased the estate of Ingress, including Ingress Abbey, from Lord Bessborough. Five years later, presumably owing to his connection with Shelburne (Adam's patron at Bowood and Lansdowne House), Calcraft commissioned Robert Adam to make designs for alterations to the house, including some interior decoration. None of Adam’s designs were executed. Instead Calcraft employed Sir William Chambers (1722-96) in c1770-72, who built a Doric temple. Chambers' temple was re-erected at Cobham Hall, Kent in 1820.

Calcraft was living at Ingress with a former actress, Mrs Elizabeth Bride, at the time of his death. The eldest of their five illegitimate children, also John Calcraft, inherited the estate. A new Tudor-style house was built at Ingress for James Harmer in 1832-34 to designs by Charles Moring (c1810-85). This house, long derelict, now forms the centrepiece of a large housing estate.